Continuous positive airway pressure (CPAP) is becoming an increasingly common way of supporting ventilation in prematurely born infants who cannot breathe without intervention. Although CPAP may be done with intubation, this invention deals only with nasal CPAP.
A problem is presented, however, in the retention and sealing of the CPAP cannula (FIG. 1) to the delicate nostrils of a premature infant. Unfortunately, a problem that may be encountered in the contact between the cannula and the delicate skin of an infant. A spot where the cannula exerts too much pressure against the skin can cause a disruption in blood flow and necrosis may begin within 10 to 20 minutes of seal application. Currently, nurses fashion CPAP seals by cutting them out of wound dressing material made by hydrocolloid laminated to a 25 micrometer thick sheet of polyurethane. The requisite process of sterilization causes wound dressing to be opaque. Accordingly, when using a seal made of wound dressing, the attending health care professionals are unable to see if damage is being done to the skin by the pressure of the cannula without at least partially removing the seal. Another instance in which an opaque seal makes it more difficult to perform a vital inspection, is in checking for an accumulation of mucous in the nostril. Such an accumulation can plug the nostril if allowed to continue accumulating, endangering the infant's life. Health care professionals check for this hazard, typically with the use of a pen light.
Another problem that is encountered in the use of CPAP seals cut from wound dressing is the challenge to medical personnel to create a seal that accurately fits the infant nose and successfully accommodates the cannula. The ideal nostril aperture size is on the order of a few millimeters. It is a challenge, even for a highly dexterous professional, to correctly form apertures of this size through the use of a pair of scissors. In addition some medical professionals make the mistake of cutting out the seal so that it is sized according to the infant nose, rather than to the cannula that will be used. While some medical professionals use a hole punch to make the holes, it is difficult to line the hole punch correctly in order to match the hole spacing with the cannula prong spacing. Also, the hole punches readily available are not sized to match the cannula prongs, making it difficult for the professional to insert the prongs either before or after placing the seal on the patient. If the apertures do not fit the cannula properly, the seal may leave a path for air leakage, or may bunch up inside the nostril, causing discomfort.
Another issue is the time that it takes to form a CPAP seal. When a newborn infant is in trouble, every second counts. Time spent cutting out a CPAP seal could delay necessary treatment for an infant. Also, even if a supply of CPAP seals are cut out in advance, a typical hospital wing has no way to hermetically enclose the CPAP seals. So the ability to store the seals is limited to a few weeks at most. Moreover, when it is time to use a seal that has been already cut out of wound dressage, the fact that the seal itself is coincident in two dimensions with the releasable liner of the wound dressing causes a difficulty in prying the releasable liner away from the dressing as there is no excess liner available to be grasped separately from the wound dressing.